Fatigue crack growth properties of carbon-polyamide 6 thermoplastic composites using a multi-?G control method

The present paper presents a new multi-?G control approach to perform mode I fatigue crack growth tests using several constant cyclic energy release rate ranges (?G) on only one specimen. It was successfully applied carbon/polyamide 6 unidirectional composite specimens. After validation checks the approach, results show that propagation behaviour exhibits three different regimes can be accurately described Hartman-Shijves equation. This work has shown method provide reliable and complete ?G versus cycles description.